Continuously feeding drying machine



Get. 17, 1933. E. H. HALL CONTINUOUSLY FEEDING DRYING MACHINE Filed Nov. 2, 1931 3 Sheets-Sheet l Get. 17, 1933. E H HALL 193mm CONTINUOUSLY FEEDING DRYING MACflINE Filed Nov. 2, 1931 3 Sheets-Sheet 2 Oct. 17, 1933. E. H. HALL CON'ZINUOUSLY FEEDING DRYING MACHINE Filed Nov. 2. 1931 3 Sheets-Sheet Patented Oct. 17, 1933 PATENT OFFICE CONTINUOUSLY FEEDING DRYING MACHINE Edward Herman Hall, Hull, England, assignor to Reckitt and Sons Limited, Hull, England Application November 2, 1931, Serial No. 572,629,

and in Great Britain October 8, 1931 3 Claims.

An application has been made for Letters Patent in Great Britain No. 27,996 filed 8th October 1931.

. The present invention relates to improvements in continuously feeding drying machines and particularly to drying machines of the vacuum type but is applicable to driersof the hot air type.

The employment of rollers to feed solid material into an air drier has already been suggested but in such proposed arrangements no attempt has been made to prevent anything but the gross passage of air from the chamber to the atmosphere.

Owing to the diiiiculty of satisfactorily feeding vacuum band driers with an even layer of solids without destroying the vacuum by allowing air to enter with the material, vacuum driers have been reserved almost entirely to those machines designed for dealing with liquids which are introduced into the machine through a series of pipes and with which it is possible to maintain a liquid seal.

The primary object of the present invention is to provide a method of sealing the drying chamer whereby a vacuum or air pressure of any desired efficiency may be obtained in the drying chamber even when feeding solid material.

Further improvements comprised in this invention relate to a novel form of feeding drying machines with an even layer of material variable in thickness at will.

With these and other objects in view the invention consists of the features of construction, combination and arrangement of parts herein after fully described and claimed, reference being had to the accompanying drawings in which:-'

Figure 1 shows a front view of the mouth of a vacuum drier fitted with seals forming the present invention,

Figure 2 shows a side View of Figure 1,

Figure 3 shows a detail view of a longitudinal seal member adapted to coact with the rollers,

Figure 4 shows a detail view of an end seal member,

sary for the return of the belt. For some material however it is possible to bring the belt sufliciently' close to the rollers to allow them to carry forward the material, Without the belt passing through the rollers. In this case only one seal is necessary.

Referring now to the drawings one or more pairs of rollers of an elastic material such as rubber are mounted in bearings positioned in adjustable supports 2 on the front face of the machine in proximity to the entrance 3 of the drying chamber 4. In the case of an endless carrier band delivering the material to be dried to said rollers a second pair or pairs of rollers (as shown in Figure 5) are arranged at the exit from the chamber. p

The roller mounts 2 are adapted to be moved relatively to one another in vertical guides 5 on the face of the machine by means of the adjusting screws 6. These screws control'the efiiciency of the seal longitudinally by regulating simultaneously the pressure between the rollers and the pressure between each individual roller and the slotted member 7, (shown in detail in Figure 3) which is mounted in solid contact with the face of the drying chamber over the entrance to said chamber and is provided with rounded edges 8 against which the peripheries of the rollers impinge.

It will be readily understood that by means of the adjusting screws 6 the pressure of the rollers against each other and against the rounded edges 8 may be adjusted until an efficient longitudinal seal is obtained. Coacting' with said pair of rollers 1 and slotted member 7, we provide end members 9 (shown in detail in Figure 4). These end members are provided with dove tailed projections 10 adapted to slide inthe corresponding dove tailed grooves formed at the ends of the slotted member 7. The said end members 9 are wedge shaped as shown in H Figure 4 and when in position in the ends of the member '7 are adapted to lie between the rollers and are provided with curved faces corresponding with the rollers and thus forming a longitudinally perfect seal at the ends of said rollers. These members are also provided with flanges 12 adapted to seal the ends of the rollers and coacting parts. The relative positions of these members 9 and the rollers 1 are adjusted by means of the adjusting screws 13 thus forming with said rollers l and the rounded edges 8 of the slotted member 7 a perfect seal which will effectively prevent air movement between the drying chamber and the outside atmosphere. Therollers are rotated in the directions of the arrows shown in Figure 2, conveniently by the chain drive 22 acting on the under roller which drive is transmitted to the corresponding upper roller through suitable gearing or a chain drive within the casing 21 (Figure 1).

In Figures 1 and 2 a band 11 carrying the material to be dried is shown as actually passing between the rollers 1. When this form of carrying band is adopted, a corresponding seal for the return of the band is necessary as stated above. For feeding some materials, however, it is not necessary for this band actually to go between the rollers. Such materials may be taken sufficiently close to the rollers for the material which it carries to be caught by them and carried forward into the drier, the band itself returning to the source of supply. In this case only one seal is necessary for feeding the machine.

In Figure 5 I show the seal built up in two stages and adapted for use where an extremely high vacuum is required. Although I have only shown the arrangement for one and two stages respectively, it will be appreciated that additional stages may be employed according to the degree of vacuum required and the nature of the material which is being fed into the drier.

Figure 6 shows by way of example a method of feeding material through seals by an endless band.

The solid to be dried is filtered from a liquid suspension by a rotary drum vacuum filter 15. The cake so deposited on the periphery of the drum 15 is removed from the filter by the scraper 16 which transfers it to the belt 11 and is carried on the top of this belt through the seal and in the case of a two stage seal, into the compartment 17 and thence into the band drier 18 where it is scraped off the scraper l9 and on to the band 20 and so through the drier. The belt 11 now stripped of its deposited solid returns to the source of supply through the seals.

If a more perfect vacuum is required than can be obtained by a two stage seal, the seal oham-- her is divided by a series of partitions into divisions with openings leading from one division of said chamber to the adjacent division and pairs of rollers of elastic material are arranged about said openings andadapted to be pressed against each other to preventair movement from one to another.

By the incorporation of a rotary drum vacuum filter described above full control over the rate of feed to the drier can be obtained by increasing or decreasing the thickness of the cake deposited on the belt 11 since withvacuum drum filters this control is perfectly maintained. Moreover the uniformity of the feed to the drier is assured in the same way.

As stated above the use of this method of feeding from a rotary drum filter is not confined to band driers or vacuum driers but can be used with any type of drier where it is desired to obtain perfect control over the rate of feed.

What I claim is:-

1. A continuous feeder for a drying machine of the vacuum or air heated type comprising a drying chamber provided with an inlet, means for feeding the material to be dried to said chamber inlet, a. slotted member with opposite rounded edges positioned over said. inlet and guiding grooves at its ends, adjustable end seals mounted in said guiding grooves at the ends of the slotted member and a pair of feeding rollers of elastic material adjustably mounted in proximity to said inlet and adapted to be pressed against each other and against the rounded edges of said slotted member and the end seals to prevent air movement between the interior of said drying chamber and the outside atmosphere.

2. A continuous feeder for a drying machine of the vacuum or air heated type comprising a drying chamber provided with an inlet, means for feeding the material to be dried to said chamber inlet, a slotted member with opposite rounded edges positioned over said inlet and undercut grooves at its ends, a pair of feeding rollers of elastic material adiustably mounted in proximity to said inlet and adapted to be pressed against each other and against the rounded edges of said slotted member to prevent air movement between the interior of said drying chamber and the outside atmosphere, adjustable end seals mounted in said undercut grooves at the ends of the slotted member adapted to seal the ends of the rollers, wedge shaped faces on said end seals curved to correspond to the peripheries of the rollers and flanges on said seals adapted to seal .1.

the ends of the rollers and their coacting parts.

3. A continuous feeder for a drying machine of the vacuum or air heated type comprising a drying chamber provided with an inlet, means for feeding the material to be dried to said chamber inlet, a slotted member with opposite rounded edges positioned over said inlet, wedge shaped seals adjustably mounted at the ends of said slotted member and a pair of feeding rollers of elastic material adjustably mounted in proximity 1. K

to said inlet and adapted to be pressed against each other and against the rounded edges of said slotted member and the corresponding surfaces of the wedge shaped end seals to prevent air movement between the interior of said dryi.(.(-

ing chamber and the outside atmosphere and means for driving said rollers.

EDWARD HERMAN HALL. 

